What does it mean when blender prints "cyclic OBU" to the console?
I figured out how to reproduce the message.


Create two objects and make one the parent of the other (maybe Cube is the parent of Sphere)
Create a second scene.
link the child object from the original scene to the new scene (I selected the sphere and used the Ctrl-L menu to do this).
Switch to the new scene.  Blender prints "cyclic OBSphere".


I suspect it's because the scene includes an object whose parent is NOT in the scene.  I have a feeling it is printing "cyclic OB%s", and this is going to make it hard for anyone googling to find an answer, since the only constant is the word "cyclic".  OB is glued to the name of the object which can vary quite a bit.  I bet "cyclic OBCube" or "cyclic OBCube.001" will be pretty common.

In my original question it was an object named "U voxel -8.0,-4.5" .

This is with blender 2.74